Monthly Archives: July 2021
Last week I heard several mention close calls on gravel roads. Please, slow down/stop before crossing unmarked intersections, fully stop at marked ones, and please remind young people of this too.
Crop Update: Keep watching silk clipping on corn that’s pollinating; rootworm and Japanese beetles clipping silks to ½” long triggers treatment thresholds. Southern rust was found in Nemaha and Greeley Counties last week from two samples at low incidence and severity. You can view updates at: https://corn.ipmpipe.org/southerncornrust/. Consultants and farmers with suspect samples are welcome to get them to me as in the past, or send to the Plant and Pest Diagnostic clinic in Lincoln. I’ve only seen gray leaf spot on the lowest leaves of fields last week so far, so disease is currently very low.
South Central Ag Lab Field Day: Reminder of this field day near Clay Center this week on July 28th which will cover nutrient, insect, disease, and weed management topics in addition to irrigation, cover crops, and biomass ones. There was a press release from UNL that had the wrong date, so just want to make sure those in the area interested in attending are clear that this will be held on July 28th from 8:45 a.m.-4 p.m. (Registration at 8:30). More details and registration at: https://enrec.unl.edu/2021scalfieldday. Walk-ins are also welcome; we just ask for pre-registration to aid in meal planning purposes.
Workshops on ag land management, leasing, carbon credits: Nebraska Extension and the University of Nebraska-Lincoln’s Center for Agricultural Profitability will host a land management workshop. It will offer updated leasing information relevant to landlords and tenants, including the latest financial trends in Nebraska agriculture, updated land values and cash rental rates for the state, strategies for equitable leasing and farm succession considerations. The latest information on carbon credit contracts for ag producers and landlords will also be discussed. The presentations will be led by Jim Jansen, an extension educator and agricultural economist, and Allan Vyhnalek, an extension educator specializing in farm and ranch transition and succession. The meeting is free to attend with meal sponsored by People’s Company, but registration is required. Locations include:
- July 28, 10:30-1:30 p.m., Extension Office, Columbus, Reg. 402-563-4901.
- Aug. 2, 10:30-1:30 p.m., Fairgrounds, Auburn. Reg. 402-274-4755.
- Aug. 3, 10:30-1:30 p.m., College Park, Grand Island. Reg. 308-385-5088.
- Aug. 17, 10:30-1:30 p.m., Extension Office, Lincoln. Reg. 402-441-7180
- Aug. 18, 9-Noon, Extension Office, Wilbur, Reg. 402-821-2151
Leaf Drop in Trees: Still receiving questions on this. For leaves such as Linden and Birch trees that have a lacy appearance of feeding on them, this is due to Japanese beetles. We hopefully are on our last week of them. For crabapple, flowering pear, ash, maples whose leaves are turning yellow/brown and dropping, this is due to fungal diseases and we wouldn’t recommend you do anything for this either. Next week I’ll talk about iron chlorosis and treatments for trees.
Brown Leaves on Oak Trees: Browning on leaf margins of individual leaves is anthracnose, which is a common fungus of shade trees. We don’t recommend that you do anything for this.
The past few years around fair time, we’ve seen oak trees (but sometimes others such as hackberry, honeylocust, elm, linden) that get a cluster of brown leaves towards the ends of branches. This damage is caused by twig girdlers or twig pruners, different types of beetles. Basically, the adult beetles chew a circle in the bark between where the old and new wood occurs on a twig. This girdles the twig, cutting off the water and nutrient supply causing its death. Eggs are then deposited and larvae hatch, tunnel, and survive in the dead twigs. Twigs girdled by any of these insects may stay attached to the main branch for several weeks or be broken out of the tree by wind. Tunneling in the twigs may not be evident in the fall if twigs fall out of the trees before the insect eggs have hatched. Mature trees with heavy infestations can look bad, but the damage isn’t a serious health problem to the tree and no chemical control is recommended. You can burn or discard infected twigs in the fall and spring that contain developing larvae to minimize the impacts for the future.
Crop Update: Grateful that in general (beyond seed corn), greensnap levels were lower for the widespread area compared to what we saw in 2020. It appears many fields with leaned plants have been working to right themselves with brace roots growing like crazy to help stabilize plants. Ear development on bent plants will be something to watch going forward. With plants bending in the wind instead of breaking, sometimes extra stress occurs where the ear is developing. Sometimes we see ear abnormalities and sometimes the ears are fine. With fields with severe bending, once the plant reaches tassel, it will no longer try to right itself and will switch to putting resources into the ear. For those with storm damaged fields who were originally planning on more nitrogen through the pivot, last year we took tissue samples to assess that need.
For fields with uneven development with plants ranging from vegetative stages to tassel, particularly storm damaged and uneven emerging fields, one needs to be aware that various adjuvants added to an insecticide and/or fungicide application pre-tassel can cause ear abnormalities.
So, the conversation with those at western bean cutworm thresholds with only portions of fields tasseling was to consider not adding the adjuvant (the same applies for those applying fungicide). I wasn’t sure how efficacy would be for different products without them (that would be a conversation for the chemical reps), but we know that adjuvants such as non-ionic surfactants can cause ear abnormalities when applied pre-tassel.
Also had several conversations regarding foliar fungicide applications. Fields have very low disease pressure right now with bacterial leaf streak being the most prevalent, and a fungicide won’t help with it. Gray leaf spot is very low in fields. Southern rust has been found in a few counties in mid- to southern- Kansas. It has not been found in Nebraska. You can view the tracking map at: https://corn.ipmpipe.org/southerncornrust/. Yield increases with automatic VT applications aren’t consistently proven in Nebraska. The following are fungicide timing studies conducted in Nebraska.
In 2008-2009, a UNL fungicide timing trial was conducted near Clay Center on 2 hybrids (GLS ratings ‘fair’ and ‘(very) good’) with a high clearance applicator. Timing over the two years included: Tassel, Milk, Dough, 25%, 33%, 50%, and 100% Dent comparing the fungicides Headline, Headline AMP, Quilt and Stratego YLD.
- 2008: No yield difference on GLS hybrids rated ‘good’ at any of the timings (Tassel, Milk, 33% and 100% Dent) nor the check when Headline or Stratego YLD were applied. For the ‘fair’ hybrid, no yield difference for any application timing nor the check for the April 30th planting except for Headline applied at milk stage (increased yield). Low gray leaf spot pressure.
- 2009: No yield difference on GLS hybrids rated ‘very good’ or ‘fair’ nor the check on any timings (Tassel, Milk, and Dough) using Headline, Headline AMP, or Quilt. Moderate gray leaf spot disease pressure.
In 2020, Dr. Tamra Jackson-Ziems and her team did another fungicide timing trial at UNL’s South Central Ag Lab near Clay Center. Fungicides were applied at planting, R1, or R3. There were no clear yield differences between applying foliar fungicide at R1 vs. R3 for any of the products except Miravis® Neo. Sometimes a product didn’t show a difference between other products or even the untreated check. There’s a picture of the data at jenreesources.com. Hybrids vary in disease susceptibility (thus response to fungicide application). With last year being a heavy southern rust year, being able to wait till at least R3 (milk) to apply a fungicide provided some additional time for the residual to work when southern really came on. I know some had to apply a second fungicide application when they automatically applied at R1. That’s just tough from an economic and resistance management perspective, in spite of higher corn prices. Thus, why I recommend waiting until disease pressure warrants the application. The main ‘plant health’ benefit observed in Nebraska when disease pressure was low (ex. 2012) was stalk strength.
July 28 South Central Ag Lab Field Day will be held from 8:45 a.m.-4 p.m. (Reg. 8:30 a.m.), near Clay Center. For all those who’ve talked with me about planting green into rye, there’s an excellent study by Dr. Amit Jhala and grad student Trey Stephens. They compare the same herbicide program with rye termination 2 weeks prior to planting or 2 weeks after planting in both corn and soybean. It was really interesting to visualize the differences in May and I’d encourage anyone interested to take a look at this now in July. Additional topics include disease, insect, and nutrient management, cover crops, and irrigation. You can RSVP at https://enrec.unl.edu/2021scalfieldday
Resiliency and Rest: Resiliency is the ability to withstand hardship. As I was thinking this past weekend about the July 9th storms and various levels of damage, I was thinking how resilient people can be with the right tools. Tools such as purpose, perspective, positive relationships (talking/checking in with others), self-awareness, and faith can be of help. Another thing I’ll throw in here is rest. The sun, heat, and humidity have been intense and exhausting. Most people I’ve interacted with have been going hard trying to keep pivots going, scout fields, and/or deal with breakdowns of various sorts. We all need rest and I hope in some way, we all intentionally take some time for that, even if just a few hours. I did that too a couple afternoons to get out of the heat, which helped me.
I was also thinking how resilient living things in general can be…such as the corn plants that bent or leaned instead of broke. I don’t have much update right now on the extent of damage as each field will vary depending on growth stage, hybrid, wind and we will learn more as we spend more time in fields this coming week. For those tracking GDD for western bean cutworm moth, you can do so at: https://mesonet.unl.edu/page/data (Select “Western Bean cutworm GDD” from the drop-down menu). Right now it’s showing GDD accumulation to not be as advanced as the CropWatch article was predicting for moth flights (was predicting 75% moth flight for York on July 13th.
Tree Damage: For those with tree damage, be sure to use the ‘3 cut method’ when trimming branches from trees. Also, look for power lines before approaching the tree. You can see a picture of this method at jenreesources.com.
Japanese Beetles or ‘something is eating my plants’ was the primary question I received last week. I’m seeing less in my landscape after the windstorm, so perhaps that helped somewhat?
The adult beetle is ½” in length with a metallic green head and white ‘tufts’ that look like spots on its abdomen. Adults feed on 300 plant species, but their favorites are ones that are in many of our landscapes (roses, cannas, marigolds, grapes, Virginia creeper, and trees such as lindens, birch, Japanese and Norway maples, cherry, plum, peach, American elm). They also feed on soybean and corn crops. They love hot weather and full sun and feed on leaf tissue during the day (leaf tissue will look skeletonized or lacy and turn brown). Trees may be severely impacted with browning occurring from the top to bottom. Thankfully healthy trees will re-leaf next year since the underlying twigs and branches aren’t damaged-even if the entire canopy is impacted this year. It’s not recommended to remove branches or trees.
DO NOT use Japanese beetle traps!!! Research shows they attract beetles to the landscape and many homeowners I’ve talked with will attest to this!
Beetle Control: Organic control options: Wait till 7-9 p.m. then knock beetles off plants into a bucket of soapy water to drown them. This method of control takes diligence over several nights. You can also spray trees with water to knock them down to the ground and then drown in soapy water. With heavy beetle infestations, it’s not uncommon to literally have scoop shovels full of the beetles when removing from trees. Neem and Pyola are two organic sprays that will protect for 3-7 days. Applying these products regularly (once per week) can also be effective as a repellent.
For conventional control options, keep in mind that Japanese beetles often impact the same flowering plants that other pollinators visit. Use insecticide products correctly to avoid damage to pollinators. Avoid spraying insecticides on windy days or when pollinators are present (best to spray late in day near dusk) and be sure to read and follow all label instructions and harvest intervals (for cherries, plums, vegetables, etc.). Conventional insecticides can provide 2 weeks of control: pyrethroid products like Tempo (Tempo can’t be used on vegetables and fruits) and Bayer Advanced Lawn & Garden Multi-Insect Killer (cyfluthrin) or Ortho Bug B Gone (bifenthrin). Sevin (carbaryl) is another option although more dangerous for bees. You can buy these products in most any farm, garden, box store…it may not be the exact products listed here, but if the active ingredient is a pyrethroid or any of those listed in parentheses above AND the product is labeled for the plant you wish to apply it to, you can apply it. Just be sure to read and follow label instructions.
Corn and Soybean Thresholds: Soybean thresholds are 20% defoliation in the reproductive stages. Thresholds for corn are: three or more Japanese beetles per ear, silks have been clipped to less than ½ inch, AND pollination is less than 50% complete. Pyrethroids are very effective against beetles. If one is concerned about flaring spidermites, a product like bifenthrin can be used.
(Adapted from: Gilbert Parra, PhD; Holly Hatton-Bowers, PhD, and Carrie Gottschalk, LMHP, MS)
How Much Time do You Have?
- Acknowledge one of your accomplishments
- Say no to a new responsibility
- Look out the window
- (adapted) Faith based prayer
- Listen to music
- Have a cleansing cry
- Chat with a co-worker, friend, or family member
- Sing out loud
- Jot down dreams
- Step outside for fresh air
- Go for a brief walk
- Enjoy a snack or make a cup of coffee/tea
- (adapted) Read faith-based devotional
- Evaluate your day, Write in a journal
- Call a friend
- (adapted) Meditate, Prayer, Devotional
- Tidy your work area
- Assess your self-care
- Draw a picture
- Listen to soothing sounds/music
- Read a magazine
Crops really look tremendous overall and got a report of some first tassels by July 4th as well! It’s been great to see people attending field days again the past few weeks and really appreciated the learning, sharing, discussion, and just watching people catch up with each other at them. I had mentioned before how the lack of freeze/thaw was impeding roots of crops, particularly soybeans in no-till fields. Irrigating and rain has helped them get some growth. What I hadn’t mentioned in my articles was being called to soybean fields with HPPD (Group 27) carryover from corn herbicides in 2020. We had a dry fall but had rain in March and May, so I wasn’t sure how to explain the carryover. One thing I learned last week from a discussion at the palmer amaranth field day was that the lack of freeze/thaw also impacts the ability of herbicides to breakdown. So, I appreciated learning that and am sharing if that helps anyone else as well.
Japanese beetles are also heavy in pockets of the area. I will share more specifics next week. For those who are asking, the threshold for soybean defoliation in reproductive stages is 20%. Tom Hunt, UNL entomologist shared that pyrethroids in general are effective. However, if there’s potential for flaring spidermites due to dry conditions, bifenthrin is a consideration as it has activity for spidermites (particularly when considering soybeans). For homeowners, beetles can be dislodged off of plants right now in evening hours by knocking them into buckets of dishsoap water. Do not use pheromone traps as they will actually attract beetles to your yard!
Western Bean Cutworm: With crops nearing tassel, it’s time to be scouting for western bean cutworm moths and egg masses. There was a CropWatch article posted this week at: https://go.unl.edu/9v4a. It was predicting 5% moth flight for York on June 30th, Harvard July 2nd, and Central City July 3. I received a text from a crop consultant saying he found the first eggmass in the Central City area July 2, so that was pretty well on target! Twenty-five percent of WBC flight occurs when 2,577 degree-days Fahrenheit are reached. Entomologists recommend field scouting should occur at this point. For 25% moth flight, it’s predicting York on July 6th, Harvard area July 8th, and Central City July 9th, so we should start watching fields for sure this week. Look for egg masses laid on the upper surfaces of corn leaves, typically on the top 1/3 of the plant.
Chiggers: I should’ve written about this last week as chigger bites tend to peak around the 4th of July with more families outdoors. Chiggers (also known as redbugs or jiggers) are the immature stages of red harvest mites. They tend to hang out in moist, tall grassy/weedy areas such as along streams, road-side ditches, forested areas, lawns. But they can also hang out in moist and dry lawns with a lot of trees too. They bite humans and other animals including pets. Eggs are laid on clusters on plants and the larvae hatch and wait for their host to come along. They latch onto clothing, shoes, and fur and can hang on while working their way to the skin (often to an area where clothing is tighter like around socks, undergarments, back of knees and under armpits). They actually don’t burrow into human flesh. They only survive on a warm-blooded host for around 3 days before falling off to molt for the next stage in life cycle which doesn’t feed on humans.
They have needle-like mouthparts that allow them to pierce the skin then inject saliva that dissolves body cells in the area to aid them in feeding. Thus, they don’t feed on blood but liquefied cells. The feeding creates an allergic reaction in which many see swelling, intense itching, and small, clustered, red bumps (which can become larger welts in some). To prevent chigger bites, avoid sitting or lying on the ground when picnicking or working outdoors. Wear loose-fitting clothing and apply a repellent like DEET to shoes, socks, and pants before going into areas more favorable for chiggers. It’s also wise to take a hot shower with plenty of soap as soon as possible after being outdoors and launder clothing with hot water before re-wearing. Also launder any blankets/sheets being used outdoors. If you receive bites, rubbing alcohol can be used then apply an anti-itch cream to help reduce itching. Thankfully chiggers can’t live in the home but they can become dislodged in bedding and on floors, so laundering bedding and vacuuming is also wise. Keep lawns and shrubs well-manicured, particularly where adjacent to dwellings. If you tend to have problems with chiggers in your lawn, they can be reduced from 75-95% for several weeks with a liquid treatment of bifenthrin. Be sure to read and follow all label instructions.